Answer: 875 g
Explanation:
There is 1000ml in 1 L. And there is 1000mg in a g. So, if 1ml contains 250mg, in 1000ml (1L) there is 250 000mg (250g). And in 3500ml (3.5L) there is 875 000mg (875g) of substance.
1000(ml) x 250(mg) = 250 000(mg) /(250g)
3500(ml)x 250(mg)= 875 000(mg) / (875g)
Therefore, 3.5L has 875g of substance.
